1. Field of the Invention
This invention relates to a toothbrush, and in particular to a toothbrush having an improved form of bristles.
2. The Related Art
It has long been known to use toothbrushes in the cause of dental hygiene, as a way of both cleaning the mouth, and also introducing a degree of freshness into the mouth. Toothbrushes typically comprise a head with a handle, with the head having a number of tufts which are used to do the actual cleaning. Typically the head comprises a number of bristle tufts which are arranged in an appropriate configuration. The bristle tufts are actually made up of a number of individual bristles which can be anchored into the brush head in any appropriate manner.
Conventional toothbrushes typically have bristles made of a synthetic material such as nylon. The nylon bristles are typically held in place in the head of the toothbrush by pins, each pin being used to anchor in place the bristles in one tuft, where the bristles in any given tuft being a number of lengths of nylon which folded in two and anchored in the middle by the pin. Once all the bristles are fixed in position in the head of the toothbrush, the distal ends of the bristles are trimmed to any convenient shape and size by known processes, for example by a revolving blade. The ends of the bristles can be of different forms to provide different cleaning benefits.
This known type of toothbrush has bristles made from nylon filaments, commonly nylon 6,12 filaments typically having a diameter of 0.15-0.25 mm, often 0.2 mm, this thickness being necessary to provide the necessary stiffness to the bristles to enable sufficient tooth cleaning to be carried out. This diameter also represents the minimum distance that can exist between bristles, and hence influences the actual area of contact between the bristles and the tooth surface. This contact area is important since the larger it is, the more efficient is the cleaning. When cleaning flat tooth surfaces with a new brush, the contact is primarily between bristle tips and the surface. In this case the actual contact area is given by the sum of individual contact areas between each bristle tip and the tooth surface. These individual contact areas result from elastic deformation of the rounded bristle tips. Finer filaments enable toothbrushes to be constructed with denser tufts and increased actual areas of contact; Such brushes are therefore more efficient.